Join Date: Nov 2008
Location: Port Moody, BC, Canada.
Yes, this is how night photography is done, if you want to have a lit foreground. You take a shot exposed for the sky, then another for foreground. Some even take a shot during twilight, then wait a couple hours (without moving the camera) and take a shot for the sky. You really need to use PS, I don't know of any other way. Well, maybe you can use ND gradient filters, but you'd be much better off by mastering blending in PS.
I don't think there should be any problem with moon moving in this case, because your shutter on the moon will likely be at least 1/200, if not faster. The shutter on the foreground can be much slower, because in that shot the moon will be masked out later in PS.